Electric elevator system



ELECTRI C ELEVATOR SYSTEM Filed May 2. 1924 2 Shuts-Sheet 1 V/ In a. W it awueutoz my M 641mm} Dec. 22, 1925.

- R. A. WAITE ELECTRIC ELEVATOR SYSTEM Filed May 2. 1924 2 Sheets-Sheet 2 Patented Dec. 22, 1925.

UNITED STATES PATENT OFFICE.

RAYMOND A. WAITE, OF YONKERS, NEW YORK, ASSIGNOR TO OTIS ELEVATOR COM- IPANY, OF JERSEY CITY, NEW JERSEY, A OORYORATION OF NEW JERSEY.

ELECTRIC ELEVATOR SYSTEM.

Application filed May 2, 1924. Serial No. 710,519.

To all whom it may concern:

Be it known that I, RAYMOND A. WAITE, a citizen of the United States, residing in Yonkers, in the county of lVestchester and State of New York, have invented a new and useful Improvement in Electric Elevator Systems, of which the following is a specification.

The invention relates to elevator systems and particularly to a system including an auxiliary motor and in which the elevator is brought to a stop level with a landing by means of the auxiliary motor should the elevator overrun or underrun the landing.

The system according to the present invention includes a hoisting drum, main motor for operating the elevator through the hoisting drum, a brake for the hoisting drum, an auxiliary motor for operating the elevator at low speeds and adapted to be connected with the hoisting drum through an electromagnetically applied clutch which is energized during such periods as power is supplied to the auxiliary motor. Means are provided for rendering the auxiliary motor inoperative except when the speed of the main motor is below apredetermined speed. By this arrangement the necessity for the clutch to absorb energy in stopping the elevator is substantially eliminated so that there is little'heating of the elements of the clutch and a compact clutch utilizing a very high operating pressure between friction surfaces may be employed.

The inventionwill. be described in connection with the accompanying drawings in which,

Figure 1 is a diagrammatic representa tion and wiring diagram of an elevator system embodying this invention.

Figure 2 is a plan view of the clutch for the auxiliary motor with portions shown in cross section,

Figure 3 is an end view of a portion of the clutch operating mechanism, and

Figure 4c is a cross sectional view taken on line 4-4 of Figure 2.

' Referring to Figure 1. the system comprises a car 10-suspended from a drum 11 operated by an electric motor 12 and having an electrically operated brake 13. The said apparatus constitutes the main driving mechanism for raising-and lowermg the elevator.

The elevator system further includes an auxiliary motor 14- adapted to be connected with the drum 11.

Its connections with p the drum include a clutch 15 which is shown 1 trolled by the car switch 19, and also an electrically operated accelerating switch C. Similar switches are provided for the auxiliary motor, namely. the direction switches UA and DA. A landing leveling switch 21, which is carried by the car 10 and adapted to be operated by cams 22 and 23 or 24 and 25, etc., is provided for controlling the auxiliary motor direction switches. The auxiliary motor also has an electrically operated accelerating switch F.

The main motor reversing switches U and D are provided with back contacts 116 and 117 which prevent the operation of the auxiliary motor when power is supplied to the main motor.

In addition to the above switches a retarding relay E is provided which is connected so as to prevent the operation of the auxiliary motor except when the speed of the main motor is below a predetermined speed. Electromagnet 28 ot' the brake 13 has connections with the direction switches for the main motor 12 and for the auxiliary motor 14 tor reliasing the brake. Electromagnet 29 of the clutch has connections with the switches UA and DA whereby this electromagnet will be energized to apply the clutch during such periods as power is supplied to the auxiliary motor.

* The clutch 15 is shown in detail in Figures 2, 3 and 4; and comprises a housing 30 secured to the end of shaft 31 of the motor 12, and carrying within it a disk 32 provided with brake linings 33. This disk is longitudinally movable within the housing but guided by means of keys 3 1 so that the two parts are rotated together. The clutch shaft 18, that is, the driving shaftfor drum 1]. when the auxiliary motor 14 is operating, carries two disks 35, and Disk 35 is shown as being formed integrally with the driving shaft 18 disposed on one side of disk 32 and provided with a plurality of pro ecting pins 37 upon which disk 36 is shdingly mounted on the other side of disk 32, between it and the inner side of the housing 30. The two disks, 35 and 86, as shown are yieldingly separated by a spring 38 so as to allow the disk 32 and housing 30 to turn freely.

A rod 39 is secured to the disk 36 and passes through a central bore in the shaft 18 to clutch operating mechanism 40 beyond the outer end of the shaft; this rod fixes the maximum distance between disk 36 and disk 35 and performs the function of moving the disk 36 so as to engage the disks 35 and 86 with disk 32 in a driving relationship. The operating mechanism 40 comprises a sp ac ing washer 41 held inan adjusted position on the outer end of rod 39 by means of the two nuts 42 and. 43 which lock it against outward movement. Between the washer 41 and the end of the shaft 18 are two sets of thrust bearings 44 and 45 of the ball hearing type and between these are mounted two cam plates 46 and 47 which are loosely journaled upon the rod 39 so as to allow the rod and various parts thereon to rotate with respect to them.

As best shown in Figure 2, the two cam plates 46 and 47 are recessed for receiving a pair of operating earns, 48 and 49, which cams as shown in Figures 2 and 3,have upwardly extending rods to which are secured lever arms 50 and 51 for turning the cams so as to separate the plates 46 and 47 and force the disks 35 and 36 into driving engagement with disk 32. The overlapping ends of arms 50 and 51 are slotted ant receive a pin for connecting'them with an extension 52 of the core of electromagnet 29.

The electromagnet 29, as shown in plan and elevation in Figures 2 and 1 respectively, is mounted on top of a journal 53 on a support 54 for the shaft 18. This electroand 51 and cams 48 and 49 is adapted to engage the disks with a high pressure density between the friction surface so as to insure a positive drive for the auxiliary motor. The clutch may be small as compared with friction brakes employed in connection with the stopping of the hoisting drum, since, as will be seen from the operation of the systern, this clutch will not be used for braking at high speeds and thus there will be neg ligible slip and little heating resulting therefrom.

Assuming that it is desired to lower the car 10 from the landing designated A to the landing designated 13, in Figure 1, and that 'a source of electrical energy is supplied through a supply switch 55 which must of course be closed during the period of opera- -circuit the starting resistance 65.

tion of the car 10, the car is started down by moving the car switch 19 so that contacts 56 and 57 thereof are bridged. This completes the circuit from the supply switch 55, by wires 58 and 59 to the car switch, through contacts 56 and 57 thereof, by Wire 60, through the coil 61 of the switch D, by wires 62 and 63 to the other side of the supply switch 55. The upper contacts of switch D close thus supplying current to the main motor 12 and to the electromagnetically released brake 13. At the same time the lower contact 116 of switch D opens to prevent the actuation of the auxiliary motor reversing switches U A and DA, The circuits thus completed are as follows: from the source, by wires 58 and 64, through the starting resistance 65, by wire 66, through contacts 67 and 68 of switch D, by wire 69, through the armature of motor 12, by wire 70, through contacts 71 and 72, by Wire 63 to the supply; and from the supply by wire 7 3 through the coil of electromagnet 28 by wire 74, contact 75, wire 76, through contacts 77, 78, 71 and 72, by wire 63 to the supply.

The operation so far described releases the brake 13 and starts the motor 12, and as the speed of the motor 12 increases and consequently its counter electromotive force, accelerating switch C is operated to short cuit is from the armature of motor 12 by wires 69 and 79 through coil 20 of switch C and by wires 80 and to the other side of the armature. As shown, the plunger 81 of this electron'iagnet is adapted to close two contacts 82 and 83 and thus short circuit the starting resistance 65. It will be understood that this resistance may be cut out by a number of steps. The retarding relay E is also connected across the armature of motor 12 by extensions of wires 79 and 80, and as the armature increases in speed relay E acts to separate the contacts 84 and 85, thereby interrupting the control circuit for the auxiliary motor 14. The motor 12 accelerates to full speed, brake 13 is held in released position, and the apparatus for the auxiliary motor drive is rendered inoperative.

As the car approaches the landing B, the car switch 19 is centered thus deenergizing coil 61 of direction switch D, the upper contacts of which then open, thereby deenergizing electromagnet 28 so as to apply brake 1 -3 and cut oil the power supply to motor 12. Upon the decnergizing of coil 61 of switch D, contacts 116 of this switch are closed. As the motor 12 slows down, its counterelectromot-ive force decreases until coil 27 ofswitch E can no longer hold its contacts 84 and open. If at this time the roller 86 of the leveling switch 21 is in The cirengagement. This will complete a circuit from the source by wires 58 and 89, through contacts 85 and 84, by wire 90, through contacts 116, by wire 118, through contacts 117, by wire 119 through contacts 87 and 88, by wire 91, through coil 92 of the switch DA, by wires 93, 94 and 63 to the source. This closes the contacts of the switch DA, for releasing the brake 13 and applying power to the auxiliary motor 14, the circuits being as follows :for the brake,from the source, by wire 73, through the coil 28 of brake 13, by wires 74 and'105, contact 106, wire 107 through contacts 108 and contacts 98 of switch DA, by wires 94 and 63 to the source; and for the auxiliary motor, from the source. by wires 58 and 109, through starting resistance 99, by wire 110, through contacts 1.11, by wire 112, through the armature of the motor 14, by wire 113, through contacts 98, by wires 94 and 63 to the source. The switch DA also has an additional set of contacts 95 which when closed complete the circuit from the source by wire '73, through the coil of electromagnet 29, by'wires 96 and 97, through contacts 95 and 98, by wires 94 and 63 back to the source. This energizes the electromagnet 29 and clutch 15 is engaged. Accelerating switch F is connected across the armature of motor 14, the circuit for the coil of this switch being as follows: by wires 112 and 114 from the armature of motor 14, through the coil 26 of switch F, and by wires 115 and 113 back to the armature. The energization of switch F cuts out the starting resistance 99 and the motor 14 operates to move the car toward the landing until the roller 86 passes off the cam 25. The cam 25 is so positioned that when the elevator has nearly reached the landing the roller 86 will roll off the cam so as to open con tacts 87 and 88 and thereby deenergize coil 92 of switch DA so as to open its contacts. Opening these contacts will apply brake 13,

deenergize the clutch electromagnet 29 so as to allow the clutch to become disengaged and cut off-the power to the auxiliary motor 14.

However, in case the elevator should have overrun its floor instead of underrunning it, the engagement of roller 100 on the level ing switch 21 will engage the cam 24 which will close the contacts 101 and 102 for operating the switch UA which switch closes the circuit through the armature of motor 14 in the reverse direction so to rotate the shaft 18 in a direction to return the car to the landing level in a similar manner to that in which the car is brought to the landing level when the car has underrun the landing.

The operation of the elevator in the up direction will be accomplished by bridging contacts 103 and 104 of the car switch 19 alternating current apparatus may be employed.

hat is claimed is 1. In an electric elevator system, the combination of a hoisting drum, a'main motor for raising and lowering the elevator, an auxiliary motor for raising and lowering the elevator at a reduced speed, means for supplying power to the main motor, means adapted to supply power to the auxiliary motor when the power supplied to the main motor is interrupted, means adapted to connect the auxiliary motor with the drum, and

means for causing the engagement of said connecting means only when power is supplied to the auxiliary motor.

2. In an electric elevator system, the combination of a hoisting drum, a main motor for raising and lowering the elevator, an auxiliary motor for raising and lowering the elevator at a reduced speed, means for supplying power to the main motor, means adapted to supply power to the auxiliary motor when the power supplied to the main motor is interrupted, means adapted to connect the auxiliary motor with the drum, means for causing the engagement of said connecting means only when power is supplied to the auxiliary motor, and means actuated in accordance with the speed of the elevator for controlling the application of power to the auxiliary motor.

3. In an electric elevator system, the combination of a'hoisting drum, a main motor connected in driving relation therewith for raising and lowering the elevator, an auxiliary motor for raising and lowering the elevator at a reduced speed, electromagnetically applied and spring released means for connecting said auxiliary motor with said hoisting drum, means for controlling the operation of the two motors and said connecting means, and means operative to prevent the operation of the auxiliary motor and the application of the connecting means therefor, dependent upon the speed of the main motor.

4. In an electric elevator system, the combination of a hoisting drum and a main motor connected in driving relation therewith for raising and lowering the elevator, an auxiliary motor adapted to be operatively connected with the hoisting drum for raising and lowering the elevator at a relatively lower speed than that at which it is operated by the main motor, an electromagnetic clutch for connecting said hoisting drum with said auxiliary motor and having its connecting members out of engagement when the elevator is at a standstill, means for controlling the two motors and said electromagnetic clutch, and means controlled by the main motor for preventing the clutch from engaging and the auxiliary motor from being operated when the speed of the drum is above a predetermined speed.

5. In a self leveling electric elevator system, the combination of a hoisting drum, a main motor operatively connected therewith for raising and lowering the elevator, means for supplying power to the main motor, an auxiliary motor for raising and lowering the elevator at a reduced speed, an electromagnetically applied clutch adapted to connect the auxiliary motor with the hoisting drum, a car switch carried by the elevator for controlling the power supplied to the main motor, a leveling switch carried by the elevator cooperating with actuating means at each landing to control the power supply to the auxiliary motor and the clutch, means for preventing the operation of the auxiliary motor and the clutch when the drum is operating above a predetermined speed, and means for stopping the drum when the power supply has been cut off from said motors and said clutch.

6. In an electric elevator system, the combination of a hoisting drum, a main motor for raising and lowering the elevator, an

auxiliary motor for raising and lowering the elevator at a reduced speed, a source of power, electromagnetic direction switches for connecting the main motor to the source of power, electromagnetic direction switches adapted to connect the auxiliary motor with the source of power, auxiliary contacts on said direction switches for the main motor for permitting the operation of said auxiliary motor direction switches when the main motor direction switches are open, an electromagnetically applied and spring released clutch adapted to connect said auxiliary motor with the hoisting drum, contacts on said auxiliary motor direction switches for energizing said clutch upon closing of either of the auxiliary motor direction switches, and an electromagnetic switch having its coil connected across the armature of the main motor to prevent energization of the auxiliary reversing switch magnets when the speed of the main motor is above a predetermined speed.

In testimony whereof, I have signed my name to this specification.

RAYMOND A. WAITE. 

